Document Details
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Document Type |
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Thesis |
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Document Title |
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ROCK MASS QUALITY FOR FOUNDATIONS OF THE NEW AJYAD HOSPITAL BUILDING MAKKAH CITY جودة الكتل الصخرية لأساسات مبنى مشفى أجياد الجديد بمدينة مكة المكرمة |
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Subject |
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Faculty of Earth Sciences - Geology Engineering |
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Document Language |
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Arabic |
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Abstract |
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The New Ajyad Hospital is situated near Al-Haram in Makkah city, which is located in the central part of the Hijaz geographic province of the Kingdom of Saudi Arabia. Makkah.
The main objectives of this study are:
Evaluating the rock mass condition for engineering purposes.
Defining the Hydrogeological Regime and assessing foundation impact.
Determining foundation level and foundation type.
The study includes geological and structural geological mapping, engineering geological mapping, geophysical investigations, geotechnical investigations, and hydrological investigations.
The geological map was drawn on a suitable scale of 1:500. Identify macro and micro structures like faults, joints etc under the site and assess their impact on groundwater movement. Engineering geological study was conducted using field measurements and laboratory tests for assessing engineering geological properties of rock units according to RMR classification system and that of soils by USCS system. The rock units were mainly Tonalitic gneiss, or deformed Granodiorite and classed as (S1-2 F1 W1-2 R1-2, A2). The rock mass is formed of light gray, medium grained Tonalitic gneiss, or deformed Granodiorite. All soils are ranging from poorly graded sand, silt with gravel on the surface to poorly graded silty sand, with fines and gravel at depth.
Geophysical Exploration Program was prepared and designed to identify the sequence of soil layers and rock units including weathered, fractured zones, and thickness and location of saturated zones and depth to groundwater, and locating the abandoned storm water tunnel passing under the site. Shallow Refraction methods were used which revealed two fracture zones. The main fracture zone exists at the southern part of the area extending in east-west with a slightly shifting to the north. Another fracture zone is indicated in the northern part. The tunnel was identified by presence of low resistivity at three locations at levels of 276, 275, and 274 masl. To confirm this two boreholes were drilled which hit the tunnel at about 275 and 274 masl. For geotechnical and hydrogeological (11) boreholes were drilled; seven in the excavated eastern part and four in the western unexcavated part. Disturbed and undisturbed samples were obtained from the boreholes. In some boreholes oriented coring was also carried out. In situ tests included SPT and falling head permeability tests in the unconsolidated units and packer tests. in rock units.
The laboratory test of soil samples included grain size analyses and unit weight. The soils are classified as silty sand .The SPT values ranged between 25 in the upper 3m to 39m in the deeper layers. Cu ranged between 3 and 19 and Cc between 0.65 and 1.12., The measured Permeability values ranged between 0.25 m/day and 8.32 m/day, by Hazen (1892).
The unit weight of rock samples ranged between 26.8 and 28.7 KN/m3. The uniaxial compressive strength ranged between 156 MPa to 200 MPa indicating the rock being very strong. The values of the Modulus of Elasticity ranged between 50 GPa to 70 GPa, with an average value of 63 GPa , whereas the Poisson’s ratio was between 0.27 to 0.34 Microstrain, with an average value of 0.30 Microstrain. Water table occurs in alluvium in the western side and in the rock in the eastern part. Water table elevation ranges between 282.0 and 285.0 masl. Piezometeric contours indicate groundwater flow generally westward into the wadi underlying Ajyad Street. The westward hydraulic gradient is quite steep and is around 0.1. The measured falling head permeability of the alluvial formation is in the range of 140 m/d and 397 m/d. The measured permeability of the bedrock is in the range of 0.02 to 0.11 m/d. The joints/fractures provide hydraulic conductivity to bedrock. Oriented coring of boreholes reveal ENE-WSW trending joints in the upper four meters and NE-SW to ENE-WSW, N-S, and NW-SE trends in the entire borehole depths. Groundwater is fresh to brackish and very hard. All the water samples indicate the same facies that is no cation-anion pair is dominant.
Keeping in view the hydrogeological regime and presence of stormwater tunnel under the site foundation can be laid at 282 masl in the excavated eastern part and at 284 masl in the eastern unexcavated part. For laying foundation excavation by blasting should not be allowed below level 285 masl. The foundation material should be environment friendly in that it should contaminate groundwater. |
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Supervisor |
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Prof. Dr. Abbas A. Al harthi |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1434 AH
2013 AD |
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Added Date |
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Tuesday, October 1, 2013 |
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Researchers
| سلطان بهلول البهلول | ALBAHLOUL, SULTAN BAHLOUL | Researcher | Master | |
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